Apparatus for regulation of heating systems.



J. A. STRATTON. APPARATUS FOR REGULATION OF HEATING SYSTEMS.

APPLIOATION FILED APR. 17, 1914.

Patented Feb. 23,1915.

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2 SHEETS-SHEET 1.

J. A. STRATTON..

APPARATUS FOR REGULATION OF HEATING SYSTEMS.

APPLICATION FILED APR.17, 1914.

1 19A. Patented Feb. 23, 1915.

2 SHEETS-SHEET 2.

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i JULIAN A. STRATTON, OF CHICAGO, ILLINOIS.

APPARATUS FOR REGULATION OF HEATING SYSTEMS.

Specification of Letters Patent.

, Patented Feb. 23, 1915.

Application filed April 17, 1914. Serial No. 832,420.

matic system, thedesirable feature of free- I dom from necessity ofperiodical attention common to such systems and, at the same time, tosecure the advantages of sensit veness and of positive and reliableoperatlon found in devices of the semi-automatic type involving the useof an auxiliary source of power, such as a mechanical or electricalmotor controlled by a thermostat.

The apparatus which I hereinafter describe utilizes for the operation ofdampers, valves or other controlling devices, the expansive forcegenerated by a volatile liquid exposed to heat, the action of the heatupon the liquid being controlled by a suitable thermostat placed at thepoint from which the temperature is to be controlled.

1 am aware that there are at present many devices depending upon thethermal expan-,

sion of liquids or gases under the influence of the heat of the heatingsystemitself or of some auxiliary source of heat, and upon the variationof such influence by means of thermostatic devices.

The novelty of my invention lies in the manner in which the applicationof the heat of the heating system to a volatile liquid is effected andcontrolled, whereby sensitiveness and powerful action are obtained witha very simple and durable construction.

The essential features are that, upon the opening of a valve controlledby a suitable thermostat, a volatile liquid is allowed to flow bygravity intocontact with a heated surface, thus vaporizing the volatileliquid, and producing the necessary mechanical force for the operationof the controlling devices by the increased vapor pressure exertedagainst a diaphragm or similar device due to its expansion. The closingof this same valve by the thermostat serves to retain theliquid fromcontact with the heated surface, and consequently tov reduce the pressure against the diaphragm or other device, by s mply trapping thecondensed vapor returning by gravity from a suitable condenser exposedto a lower temperature, thus preventing the liquid coming into contactwith the heated surface until the valve is again opened by thethermostat.

The form which the apparatus may take W111 vary considerably, of course,depending upon thepurpose for which it is applied and the conditionsunder which it is required to operate, as well as upon the form ofcontrolling thermostat used. The essential features of operation,however, remain the same.

In the drawings illustrating the princiregulating apparatus; Fig. 2 is adetail showing' a modification of the expansion chamber and theconnection of the thermostat therewith; Fig. 8 illustrates a'modifiedform of my new apparatus; and Fig. 4 is a detail which illustrates amodified form of safety device and thermostat connection for use withthe apparatus shown in Fig. 3.

Referring to the drawings, a suitable receptacle or chamber 1 is placedso as to be exposed preferably to the internal heat of the heatingsystem to be regulated, although an auxiliary source of heat may beemployed, if desired. Thus, when the system is used for controlling thedampers of steam or hot-water boilers, the chamber 1 may be placedwithin a shell A and in contact with the furnace gases or with the steamor hot water; while in the case of hot-air furnaces, it may be placed incontact with the heated air or furnace gases. When used to control thetemperature in some part of a heated area by controlling-valves ordampers in the service pipes, the chamber 1 would be placed so-as to beexposed to the heat of the steam, hot water or air as the case might be.The chamber 1 is connected by a pipe 2 with the chamber 3 removedsomewhat from the influence of the heat acting upon the chamber 1. Thechamber 3 has a reservoir 4 in which the .volatile liquid may betrapped. Throughthe side of the reservoir 4 extends a rod 5 carrying avalve member 6 which rests normally against its seat 7, thereby closingthe opening 7 The rod 5 is attached at its ends to two flexiblediaphragms 8 and 9 of thin metal with circular concentric corrugations8' to increase the flexibility. By means of these diaphragms, motion maybe communicated to the rod 5 from outside the apparatus without loss byfriction or the possibility of leakage of vapor which might occur, ifstufling boxes or pistons were used. Two opposite diaphragms of equalarea are here used for the purpose of neutralizing the effect of anyvariations in vapor pressure, within the chamber, upon the rod 5 and inorder to prevent interference with the proper action of the controllingthermostat. The valve 6 is held normally against its seat 7 by a lever10 pressed against a projection 9 on the diaphragm 9 by the tension ofthe spring 11, which is adjustable by means of the thumb-nut '12. Thechamber 3, by an opening 3 over the reservoir 4, communicates with themultiple diaphragm 13, which consists of a plurality of thinconcentrically corrugated metal dia-,

phragm-like disks 13 connected at their centers by tubular members 13'',as shown, to form a continuous passage. The object of this arrangementis, of course, to provide for a large range of motion. As the object ofthis multiple diaphragm 13 is simply to convert the variations in vaporpressure within the chamber-into mechanical motion for the operation ofthe regulating devices, it is evi-v dent that I may replace it by anydevice capable of performing substantially the same function insubstantially the same manner; such as, for example, a different type ofdiaphragm, or a cylinder and pi'ston, etc. However, as this multiplediaphragm also serves the purpose of a condenser 'for the vaporgenerated from the volatile liquid, it would be necessary to provide aseparate condenser or else arrange the chamber 3 for that purpose, inthe case of the substitution of some device which .been reached, thechain 21 will be drawn taut and the lever 10 be pressed more stronglyagainst the diaphragm 9, thereby closing the valve 6 against the actionof the thermostat and so preventing any further flow of liquid into thechamber 1 and thus .any further rise in pressure. As a furtherprecaution, the rod 14 is shown indirectly connected to the lever 15through the spring 16, which presses at its upper end against theslidable washer 17 and at its lower end against the fixed projection orcollar 18 on the rod 14. This spring 16 is sufficiently 'stiff totransmit without appreciable distortion the necessary pressure foroperating the controlling devices through the lever 15, In case,however, such devices become stuck or, for any reason, the lever 15cannot be moved, the spring 16 is compressed against the washer 17,allowing the rod 14 to slide through the opening 15 in the lever 15, andthus closing the valve 6 by means of the chain 21.

The operation in detail is as follows: The reservoir 4 normally containsa volatile liquid such as ether, carbon bisulfid, alcohol, water or thelike, depending upon the temperature conditions under which the deviceis to operate. This liquid is chosen to have a boiling point somewhatbelow the temperature to which the chamber 1 is exposed and which may,for example, be the minimum operating temperature of the heating systemat which regulation becomes necessary, but above the temperature towhich the multiple'diaphragm or condenser is exposed; this may, forexample, be the temperature of the boiler room. The valve 6 is normallyclosed, thereby trapping the liquid in the reservoir 4. If thetemperature of the heated area rises above a certain point, a suitablethermostat is brought into action in the manner hereinafter described,whereby pressure is exerted against the projection on the diaphragm 8,thus slightly raising the valve 6 from its seat 7. This movement allowsa small quantity of the volatile liquid to trickle through the opening7' and flow by gravity down through the tube 2, coming into contact withthe heated walls of the chamber 1. Here it vaporizes, raising thepressure in the chamber 5 and expanding the multiple diaphragm 13,whereby the rod 14 is raised and the controlling devices are operatedthrough the lever 15. As the temperature of the multiple diaphragm 13,which is located so as to be removed from the influence of the heatsurrounding the chamber 1, is lower than the boiling point of theliquid, a continual condensation takes place, the condensed liquid beingreturned to the reservoir through the opening 3 locoated in the top ofthe chamber 3, as shown. As long, however, as the valve 6 is held openby the thermostat, the returned liquid trickles through the opening 3"in the bottom of the chamber 3 and is again vaporized in the chamber 1,the parts being so proportioned that the desired pressure is maintainedagainst the lever 15 under these conditions. If, on account of a fall inthe temperature in the heated area, the thermostat releases the pressureacting upon the diaphragm 8 and allows the valve 6 to be closed lli.pensed with and by the spring 11, the returning liquid is trapped inthe reservoir and prevented from flowing into the chamber 1. Ascondensation still continues in the multiple dia phragm 13, the vaporpressure rapidly falls again to normal, thereby restoring the lever 15and the controlling devices controlled thereby. The area of the passage2 between i the chambers 1 and 3, and-the area also. of that between thechambers 3 and 13, are proportioned so that suflicientspace is allowedfor the passage of vapor and condensed liquid in op osite directionswithout appreciable trans er of heat by gaseous convection from chamber1 to chamber 3.

It is evident that the elementsmarked 16 to 21, both inclusive, performthe function simply of safety devices and may be disthe rod 14- may thenbe directly connected to the lever 15 in any suitable manner, providednecessary precautions are taken to prevent an excessive rise ofpressure. For example, the quantity of liquid within the reservoir 4 maybe so proportioned that, even if all the liquid above the valve opening7 is allowed to flow into the chamber 1, the pressure will not rise to adangerous point; or the valve opening 7 may be made so small that, evenwhen the valve is held continually open, the rate of flow of the liquidinto the chamber 1 will be slow enough so that condensation in themultiple diaphragm 13 will prevent excessive pressure; and so on.

As the function of the thermostat is simply to operate the valve 6, itis evident that any form ofthermostat capable of doing this may be used.While in order to make clear the principle of operation and theapplication of my device, I have described cer-' tain forms ofconstruction the use of which I consider advantageous, it will beunderstood that I am not limited to the use of these forms but mayemploy any other form, provided its functions. are essentially thosedescribed. I shall now describe one form of thermostat.

Referring again to Fig. 1, the cylindrical wall of the chamber 22 isprovided with radiating flanges 22 tiveness; and this chamber 22 islocated at the point from which the temperature is to be controlled. Aflexible diaphragm 23, which is similar to the diaphragms 8-and 9 andagainst which the lever 25 is pressed by the spring 26, is adjustable bymeans of the thumb nut 27, which engages the threaded endof a pin 26 towhich one end of the spring 26 is attached and which passes slidablythrough a hole 26 in the.

bracket-arm 25 that projects from the box 22. The other end of the lever25 is connected by the chain 28 to the lever 29 which is fulcrumed at 29on a bracket 29" and which bears against the diaphragm 8. The

"shown). to increase the sensichamber 22 is-partly filled with a liquidthe. boiling point of which is below the minimum temperature of therange over which the thermostat is required to work. There will existthen in the chamber 22, at any temperature within this range, a certainpressure which is the'vapor pressure'of the given liquid at thattemperature. The diaphragm 23 is held against the stop 24 by the tensionof the spring 26. This sprin tension is so adjusted by the thumb nut 2that, when the temperature surrounding the thermostat rises to the pointat which it is desired the thermostat shall operate the valve 6, thevapor pressure within the chamber 22 forces the diaphragm 23 away fromthe stop 24,.thereby pressing down the lever 25 against the action ofthe spring 26 and drawing the chain 28 tight and o ening the valve 6.When the temperature alls below the critical oint, the-spring 26 forcesthe diaphragm ack against the stop 24 and releases the tension on thechain 28, allowing the valve 6 to close. In operation the valve 6 is notopened widely and closed again with the variations in temperature at thethermostat, but is rather held a suflicient distance from its seat 7 toallow the liquid to trickle through at a rate which will produce thenecessary pressure to hold the controlling devices at the proper pointto give the desired temperature.

Fig. 2 shows a modification of the expansion chamber 3 of Fig: 1 for usewith a form of thermostat arranged so that the controlling pressurevariations are trans mitted from the thermostatthrough a tube containinga gas, liquid or vapor. In Fig. 2, there are shown a .section 31 of theexpansion chamber corresponding to the chamber 3 of Fig. l; and thevalve-rod 5' which controls the diaphragm 30 corresponding to thediaphragm 8 of Fig. 1. On the outside of the chamber 31 and surroundingthe diaphragm 30, there is arranged a chamber 32 which contains aliquid, gas or vapor and is connected by means of the tube 33 with asuitable thermostat (not The pressure variations set up by thethermostat are thus transmitted to the diaphragm 30. With thearrangement shown, the volume of fluid contained between the walls ofthe chamber 32 and the diaphragm 30 should-be as small as possible tominimize variations in pressure due to heat transmitted through thediaphragm. The tube 33 may also be of small bore and curved as shown toprevent transfer of heat by convection. If desirable further to avoidtransfer of heat, separate diaphragms suitably connected may be used orthe fluid may be kept from contact with the diaphragm by a flexiblelayer of non-conducting material or the like as will be readilyunderstood by those skilled in the art.

Fig. 3 shows a'modification of the structure illustrated in Fig. 1, foruse in valve 40 by the rod 41.

in vapor pressure in the expansion cham- 9.

her. The form of thermostat'representative of this type'is here shown bya coil of tubing or a flanged chamber 34 closed at one end by a flexiblediaphragm 35 and connect- ,ed by means of a tube 36 (preferably of smallbore) with the auxiliary chamber 37 formed'on the expansion chamber 3".A flexible diaphragm 39 is connected to the This valve 40 is normallyheld against its seat 40 by the spring 42 which presses at one endagainst thevalve 40 and at its other end against a lug 43 through whichpasses a guiding rod 44. The diaphragm is pressed upwardly by the spring46 and its upper surface is in contact with the screw 47. The chamber34, thetube 36 and the space 39? beneath the diaphragm 39 are entirelyfilled with a suitable fluid, such as an oil having a high coefiicientof expansion. The pressure of the liquid in the chamber 34 and againstthe .diaphragm 39 is adjusted by means of the screw 47, which bearsagainst the flexible diaphragm35. This screw 47 is so adjusted that,when the temperature in the chamber 34 rises to thepoint at which it isdesired the thermostat shall operate, the increase in pressure due tothe expansion of the liquid in the thermostat will raise the valve(preferably of large area) against the pressure of the spring 42. Thisallows the volatile liquid contained in the expansion chamber 3 to flowinto the auxiliary chamber 37 and thence through the by-pass or opening48, into the tube 2 and finally into the vessel or chamber 1, as in thestructure illustrated in Fig. 1. The tube 2 is extended above the levelof the liquid in the expansion chamber 3* to prevent the condensed vaporreturned from the multiple diaphragm or condenser 13 from reaching thechamber 1 except through the valve 40. The multiple diaphragm 13 isconnected to the controlling apparatus through the rod ll in anysuitable manner. Since practically incompressible liquid is employed inthe thermostat, and as the diaphragm 35 bears firmlyagainst the screw 47at all times, the variations in pressure against the upper surface ofthe valve-controlling diaphragm 39 due to variations in vapor pressurein the expansion chamber 3 do not interfere with the action of thethermostat, and a compensating diaphragm is not necessary. It isdesirable however that the chamber 34:, the tube 36 and space 39 beentirely filled with the liquid; for, a small air-pocket would takeup-the variations in volume of the liquid so that the valve would not beoperated. The same desirability of minimizing the transfer of heatthrough the diaphragm 39 exists, of course, as in the arrangement shownin Fig. 2.

Fig. 4 shows a safety device which is of di erent type and which isillustrated as applied to the arrangement shown in Fig. 3. The chamber50 is closed at its top by the flexible diaphragm 51, which is connectedto the valve 52 by the rod 53. The bottom of this chamber 50 isconnected to a flexible diaphragm 54 which is located in the bottom ofthe chamber 55 and which is held against the stop 56 by means of thespring 57. The tube 58 is connected with the chamber 50and a thermostat(not shown) and is 'formedinto a coil 58* within the chamber 55, asshown, to provide flexibility. Normally the operation is the same asthat of the structure shown in Fig. 3, the valve 52 being raised by thediaphragm 51, and thereby allowing the volatile liquid to flow throughthe by-pass 59 into the tube 2". The pressure of the spring 57 is soadjusted, however, that, in case the pressure within the expansionchamber 55 becomes excessive, the diaphragm 54 is forced downwardly andaway from the stop 56, thus lowering the chamber 50 and closing thevalve 52 and thereby stopping the flow of liquid. Such a safety devicemay, however, be dispensed with by properly proportioning the quantityof'volatile liquid, size of openings, etc.,

desired type and, furthermore, that auxiliary devices other than thosedescribed may be employed; as, for example, thermostats withtime-operation features may be used.

This apparatus may be employed for any purpose of regulation in which atemperature variation is the determining factor by placing thethermostat so that it will be exposed to the action of such temperaturevariation and arranging so that the movements of the multiple diaphragm(or similar device) are communicated'to suitable devices for regulatingdraft, supply of fuel, flow of liquids from the tanks, etc.

With regard to the advantages which 1 claim for the above-describedsystem over existing systems,.it will be noted that the thermostat isonly required to open slightly a small valve, which is practicallybalanced,

as the vapor pressure on both sides isthe same, thus giving asensitiveness equal to those systems in which a thermostat is used totrip a weight and start a motor or clockwork, without the disadvantageof requiring winding, renewal of batteries, etc. There is the furtheradvantage that, with the arrangement described, the controlling devicesare held at a point to maintain the proper temperature with slightmovements in either direction, instead of being shifted back and forthover a considerable range, thus giving closer regulation and greatereconomy of fuel when applied to the regulation of the draft of a furnaceor boiler.

The use of the thermostatically-controlled valve for bringing by gravitya volatile liquid into contact with a source of heat and its removal byevaporation and condensation, makes available for producing themechanical forces necessary to operate controlling devices the entirerange of temperature between the external and internal temperatures of aheating system, thus giving, with respect to positive and reliableoperation, a great advantage over systems in which the considerablemechanical force necessary to properly operate the control ling devicesmust be generated directly by the small allowable variations in, thetemperature which is to be controlled.

With regard to the mechanical features of the system it will be notedthat the use of flexible diaphragms as described obviates themaintenance difliculties and possibility of leakage due to use ofstuffing-boxes and, furthermore, that only one valve is necessary forthe operation of the system and that this valve is not'required toremain tight against gas or vapor pressure but only against thehydrostatic pressure of an inch or so of liquid, thus requiringpractically no attention. While I consider the use of a flexiblediaphragm or diaphragms as described to be a very desirable means ofactuating the valve ofthe apparatus, it will be understood that othersuitable means may be employed if desired.

I claim:

1. An apparatus for the automatic regulation of heating systems,including a reservoir for holding a volatile substance; a vaporizingchamber adapted to receive the latter; means controlling the flow of thevolatile substance .from said reservoir to said chamber; a thermostatfor controlling said means; and heater-controlling mechanism actuated bythe pressure of the vapor into which said substance is converted by theheat of said chamber.

2. An apparatus for the automatic regulation of heating systems,including a reservoir for holding a volatile substance; a vaporizingchamber adapted'to receive the latter; means controlling the flow of thevolatile substance from said reservoir to said chamber; a thermostat forcontrolling said means; an expandible device which is in communicationwith said chamber and is adapted to receive the vapor flowing therefrom;and heater-controlling mechanismactuated by said device.

3. An apparatus for the automatic regulation of heatingsystems,including a reservoir for holding a volatile substance; a vaporizingchamber adapted to receive the latter; a valve controlling the flow ofthe volatile substance from said reservoir to said chamber; a thermostatfor controlling said valve; and heater-controlling mechanism actuated bythe pressure of the vapor into which said substance is converted by theheat of said chamber.

4. An apparatus for the automatic regulation of heating systems,including a reservoir for holding a volatile substance; a vaporizingchamber adapted to receive the latter; means for controlling the How ofthe volatile substance from said reservoir to said chamber; a thermostatfor controlling said means; a safety device for controlling said means;and heater-controlling mech-T anism actuated by the pressure of thevapor into which said substance is converted by the heat of saidchamber.

5. An apparatus for the automatic regulation of heating systems,including a reservoir for holding a volatile substance; a vaporizingchamber adapted to receive the latter; means controlling the How of thevolatile substance from said reservoir to said chamber; a thermostat forcontrolling said means; a condenser for condensing the vapor flowingfrom said chamber; and heater-controlling mechanism actuated by thepressure of the va or into which said substance is converted y the'heatof said a chamber.

In testimony whereof I have hereunto set my hand at Chicago, Illinois,this seventh day of April A. D., 1914, in the presence of

